The actor Emily Blunt has apologised for saying that she regretted becoming an American citizen after watching a Republican party presidential candidacy debate.

The British-born Devil Wears Prada and Sicario star said the remark was a joke, after being attacked by rightwing commentators.

During an interview with the Hollywood Reporter at the Toronto film festival, Blunt joked: “I became an American citizen recently, and that night, we watched the Republican debate and I thought, ‘this was a terrible mistake. What have I done?’”

She made the comments during a video interview alongside a host of other actors, including Bryan Cranston, Naomi Watts and Ellen Page. During the mainly lighthearted discussion, they were asked to discuss America’s political landscape and to choose people from Hollywood they thought could run for president.

Blunt’s comments followed an interview with Jimmy Kimmel on his Live programme, during which she poked fun at her new status. She joked that British people tend to look down on Americans and that she had lost the right to do so by taking US citizenship.

She said: “I’m not sure I’m entirely thrilled about it. People ask me about the whole day. They were like, ‘oh, it must have been so emotional’. I was like, ‘It wasn’t, it was sad’. I like being British.

“I had to renounce my Queen. The thing that’s weird is I do get to keep both my British citizenship and this, but you have to renounce her. But it’s kind of typically American – not to be rude. I had to renounce her in the room but I don’t actually technically renounce her. They were like, ‘just say it, you don’t have to mean it but just say it’.”

Blunt also took a mock “real citizenship test” on the chatshow, in which she was asked what the giant refillable sodas at 7-11 were called and what the acronym MLB stood for.

Her remarks to the Hollywood Reporter were included in a news item by Fox News on its Fox & Friends programme. Its presenter, Anna Kooiman, took offence to them, sighing and saying: “Well, you know what? Why don’t you leave Hollywood, California and let some of the American women take the roles that you’re getting because American citizens are watching your movies and lining your pockets.”

She was backed up by her colleague Steve Doocy, who said Blunt had “alienated half the country” and that people would “now think twice before going to one of her movies”.

Blunt, who lives in the US with her husband, John Krasinski, and their child, sought to set the record straight in an interview with NBC’s Today programme. She said: “It was so not the intention to hurt anybody or cause any offence, so I really apologise to those that I caused offence to.

“It was just an off-hand joke. I think I’ll probably leave the political jokes to [talk show] Late Night or something.”